1. Field of the Invention
The present invention relates to an image forming apparatus such as a digital plain paper copier, etc. which reads a document image by scanning a document and forms a reproduced image corresponding to the read document image on a paper.
2. Description of the Related Art
On a digital plain paper copier (DPPC) as an image forming apparatus, a program is compressed and stored in a mounted ROM in order to reduce its capacity. In case of a digital plain paper copier, after the power source is turned ON, a program is first expanded and then, executed and the copier is operated.
On an image forming apparatus which compresses a program in order to reduce its capacity, the program that was compressed and stored in a ROM or a hard disc was so far expanded using a boot program that is for starting up a computer incorporated in the image forming apparatus and was then stored in a RAM. In this case, the display on the control panel to make the input is made by a program stored in the RAM. Therefore, if a program was large, a time was required for the expansion of it and user had to wait until the indication was presented on the control panel and tended to misconceive that the power source is not properly turned ON.
That is, on a conventional digital plan paper copier, a CPU reads a compressed program out of a ROM when the power source is turned ON. After expanding the compressed program read out of the ROM, the CPU stores the expanded program in the RAM. When expanded programs are all stored in the RAM, the CPU starts to execute the expanded program on the RAM and executes a program to transfer display data to the display of the control panel. When the program to transfer the display data is executed, the data is displayed on the display of the control panel.
Further, if it is necessary to check that a specific key is pressed by an operator when the power source is ON, a conventional digital plain paper copier had such a problem that the operator must continuously push the key until the expanded program starts to operate.
As mentioned above, when the power source is ON, the digital copier discriminates whether it is the normal power ON or it is turned ON by an operator for making the adjustment and changes subsequent processes accordingly. For instance, if a specific key is pushed when the power source is ON, an adjustment program for operator is started. If no key is pushed, it is regarded to be a normal start.
That is, on a conventional digital copier, when the power source is turned ON and a reset signal is input, a CPU reads a compressed program from a ROM. Then, after expanding the program, the CPU stores the expanded program in a RAM.
When all programs are expanded and stored in the RAM, the CPU starts the operation according to the expanded programs and starts to execute an analyzing program of the control panel. The CPU checks if a key of the control panel is pushed and when it is pushed, makes the display for an operator on the display of the control panel and starts the operation for operator.
Further, if the control panel key is not pushed, the CPU displays the normal screen on the display of the control panel and starts the normal operation.
As mentioned above, a conventional digital copier had such problems that a time was required until the display appeared on the display of the control panel or a time was needed until the check to see whether the control panel key was pushed when the power source was ON. In particular, when detecting that the control panel key was pushed when the power source was ON, there was such a defect that a key had to be kept pushed until the program expanding was completed, the expanded program was started and the control program analyzing program was started.
As mentioned above, on an image forming apparatus which compresses a program and stores it in a ROM in order to reduce its capacity, a program that was compressed and stored in a ROM or a hard disk by a boot program that is to be first executed when the power source is turned ON is expanded and stored in a RAM. However, if a program is in a large, a time is required to expand it and therefore, user had to wait until the display appears on the display of the control panel. Moreover, there was such a problem that user is apt to misunderstand that the power source is not properly turned ON and further, when it is necessary to check if a specific key is pushed when the power source is turned ON, user must push a key continuously until an expanded program begins to operate.
It is an object of the present invention to provide an image forming apparatus which makes a quick display on the display portion of a control panel without requiring to continuously push a specific key when the power source is ON and programs are compressed and stored in a ROM.
According to the present invention, an image forming apparatus configured to form an image by reading an image on a document, comprising a control panel having a display configured to receive an input data, a memory configured to store an initial display data of the control panel and a compressed program, a power source detector configured to detect that the power source is turned ON, and a controller configured to control the initial display made on the display of the control panel by reading initial display data of the control panel stored in the memory when the power ON is detected by the detector.